The present invention relates to measuring of machine cycle times for a manufacturing facility. More particularly, the present invention relates to automatic capturing and measuring of machine cycle times to perform a detailed analysis.
Each machine or piece of equipment in a manufacturing environment is responsible for performing one or more steps or operations in the production process. The time required to complete a particular step or series of steps is known as the cycle time. Monitoring of the machine cycle times for machinery in a manufacturing environment is helpful in reducing manufacturing costs and increasing the quality of products that are produced. Monitoring and recording of cycle time data is useful in detecting malfunctions and maladjustments in the manufacturing machinery. Machine cycle times that fall below or exceed specified tolerances or standards are indicators of machine or equipment problems that may result in-product defects. It is possible that certain steps or operations in the manufacturing process are not starting at all or are stalled. Even if the resulting products are not defective, if the machine cycle time is too long, the additional time needed to produce the products is costly.
Systems and methods for monitoring machine cycle times are known. However, in known system and methods, it is difficult to control which steps in the manufacturing process are measured and how they are measured. In many instances, machine cycle times are monitored manually by an operator with a stopwatch. The operator watches for start and stop events and records the elapsed time between the start and stop events. Attempts have been made to automate the monitoring process. U.S. Pat. No. 4,583,280 to Corrigan discloses a system and method for measuring and recording time cycles for each manufacturing step performed at a station. However, operators have very little control over which steps are monitored and how they are monitored. U.S. Pat. Nos. 5,586041 and 5,893,047 relate to monitoring of machine operations, but do not relate directly to monitoring machine cycle times. As with other prior art systems, the disclosed systems do not provide operators with control over which steps in the manufacturing process are monitored and how they are monitored.
The present invention is a cycle time analyzer system that monitors machine events (analog or digital) and calculates elapsed times for these events. The system and method allow an operator to setup and recall process configurations that define the machine events to be monitored. The process configurations comprise machine event descriptions along with respective programmable logic controller addresses that define the start and stop of an event. Each event relates to a step or operation performed by the machine (e.g., shuttle lift up, shuttle lift down). The operator also defines a standard time or tolerance for performing the step. The operator may further specify whether cycle times for a series of events are to be accumulated. Finally, the operator has the option of saving the collected data to a file that may be recalled for analysis and printing.
The features and functionality of the present invention provide an operator with control over which steps are monitored and how they are monitored. When a problem is detected, an operator has the option of defining additional process configurations based on a subset of the steps monitored previously. As a result, the operator may pinpoint the source of a problem by focusing on a particular set or series of steps. The ability to control the monitoring process through the process configurations provides greater flexibility to the operator and increases the usefulness of machine cycle time monitoring.